Vacuum pumps are powerful tools because the atmospheric pressure on our planet’s surface is strong. That pressure is enough to crush evacuated vessels with impressive implosive force. At less extreme pressure differences, [hopsenrobsen] shows us how to cleverly use kitchen materials for vacuum molding fiberglass parts in a video can be seen after the break. The same technique will also work for carbon fiber molding.
We’ve seen these techniques used with commercially available vacuum bags and a wet/dry vac but in the video, we see how to make an ordinary trash bag into a container capable of forming a professional looking longboard battery cover. If the garbage bag isn’t enough of a hack, a ball of steel wool is used to keep the bag from interfering with the air hose. Some of us keep these common kitchen materials in the same cabinet so gathering them should ’t be a problem.
Epoxy should be mixed according to the directions and even though it wasn’t shown in the video, some epoxies necessitate a respirator. If you’re not sure, wear one. Lungs are important.
[Patrick] is using a capable 380KV Propdrive motor, capable of pushing him up to 30mp/h! A waterproof 120A speed controller and 6000mAh, 22.2V LiPo battery slim enough to fit under the board give the motor the needed juice. He ended up buying the cheapest RF receiver and remote combo to control the board, but it fit the all-important “want electric long board now” criterion.
The mechanical and electrical feats accomplished by [transistor-man] may not be the most impressive parts of this hack. We’re pretty impressed by the build, starting as it did with the big knobby tires and front truck from an unused mountain board and the hub motor from a hoverboard, turning this into a trike. The incredible shrinking chassis comes courtesy of a couple of stout drawer slides and cam locks to keep it locked in place; collapsed, the board fits in a carry on bag. Expanded, it runs like a dream, as the video below shows.
But we think the really interesting part of this hack is the social engineering [transistor-man] did to ensure that the authorities wouldn’t ground his creation for electrical reasons. It seems current rules limit how big a battery can be and how many of them can be brought on a flight, so there was a lot of battery finagling before his creation could fly.
Electric longboards look like a real kick, whether they be all-aluminum or all-plastic, or even all-LEGO. This one, which went from concept to complete a week and a half before the flight, really raises the bar.
The Hackaday Prize is in full swing, and that means we’re starting to see all the builds a few select people have been saving up for the past few months. [yowhwui] has been working on a 3D printed electric longboard for a while now, and this build is really solid. He already has over 150km on the odometer, and the 3D printed parts are still holding up.
The power for this motor comes from a 6374 brushless motor running at 192 kV. This, plus two 4S 30C 5000mAh LiPo batteries propel this longboard to speeds up to 42 km/h (2.18 Saxon leagues per quarter hour), all while weighing about 8kg.
Since [yowhwui] is using the motor for power and braking (electric motors are neat), this longboard needs to be designed with belt skipping in mind. To that end, he’s designed a drive system with an idler, and nearly every single part is 3D printed. The first revision of the hardware was printed in PETG. While PETG was more than strong enough, it was also too brittle. This led to a few cracks. After printing the parts out again in ABS, [yowhwui] put a few more kilometers on this longboard, and there are no immediate signs of wear.
Looks like electric longboards are becoming a thing, with increasingly complex electronics going into them to squeeze as much performance as possible out of them. When an electric longboard lasts for 35 miles, can longboard hypermiling be far behind?
If endurance longboarding sounds familiar, it’s because we just covered a 25-mile electric that outlasted its rider. To get the extra 10 miles, [Andrew] cheated a little, with a backpack full of extra batteries powering his modified Boosted Board, a commercially available electric longboard. But the backpack battery was only a prototype, and now [Andrew] is well on his way to moving those batteries to a custom underslung enclosure on his new “Voyager” board. Eschewing balancing and monitoring circuitry in favor of getting as many batteries on board as possible, [Andrew] managed sixty 18650s in a 10S6P configuration for 37 volts at 21 Ah. He didn’t scrimp on tools, though – a commercial terminal welder connects all the battery contacts. We really like the overall fit and finish and the attention to detail; an O-ring seal on the 3D-printed enclosure is a smart choice.
Voyager isn’t quite roadworthy yet, so we hope we’ll get an update and perhaps a video when [Andrew] goes for another record.
What could be better than a holiday ride past the palm trees and blue waters of a Mediterranean resort town? Perhaps making that ride on a long-range electric longboard of your own design will ice that particular cake.
And when we say long range, we mean it – an estimated 25 miles. The only reason [overclocker_kris] couldn’t come up with an exact number in the test drive seen below is that he got too tired to continue after mile 20. With a bit of juice left in the 64-cell battery pack, built from 18650s harvested from old laptops, the board was sure to have another five miles in it. A custom molded underslung carbon fiber enclosure houses the battery pack and electronics, including the receiver for the handheld remote control and the ESCs for the two motors. Motor mounts were fabbed from aluminum and welded to the trucks, with power transmission through timing belts to 3D-printed pulleys. It’s a good-looking build, and topping out at 22 MPH isn’t too shabby either.
[Tallaustin] worked at Stratasys as an intern this past summer. They let him know that he was welcome to use their fancy industrial printers as much as he’d like. Not to waste such an opportunity he promptly got to work and designed an electric longboard, printable for a mere $8,000.
[Tallaustin] is presumably tall, and confided to Reddit that he weighs in at 210 lbs. For those of us who have had the pleasure of designing for FDM 3D printing, we know that getting a skateboard one can actually skate on without it delaminating somewhere unexpected is pretty difficult if you weigh 80 lbs, 200+ is another category entirely. So it’s not surprising that his first version shattered within in moments of testing.
So, he went back to the drawing board. Since he had his pick of all of Stratasys’s most expensive and fine spools of plastic, he picked one of the expensivest and finest, Ultem 1010. Aside from adding a lot of ribbing and plastic, he also gave it a full rundown with some of SolidWorks’s simulation tools to see if there were any obvious weak points.
Six days of exceedingly expensive printing later, he had a working long board. The base holds some batteries, an ESC, and a 2.4 GHz transceiver. The back has a brushless motor that drives a pulley slotted into one of the wheels. The rest is standard skateboard hardware.
If you’d like to build it yourself he’s posted the design on Thingiverse. He was even nice enough to put together a version that’s printable on a plebeian printer, for a hundredth of the price.